IT9052976U1 - HEAT EXCHANGER FOR REFRIGERATOR - Google Patents

Description

DESCRIPTION

The present invention relates to a heat exchanger which can be used, for example, in the "freezer" or freezing chamber of a refrigerator and more particularly a heat exchanger having a greater cooling power to allow the freezing chamber to serve as a chamber. quick freezing.

a refrigerator of the generally used type, for example of the refrigerated air circulation type, a cooling chamber is arranged in the innermost part of the freezing chamber. Various parts are housed in the cooling chamber such as a primary coolant, a blower and so on. During operation, air is forcibly supplied by the blower to the primary refrigerant - and the refrigerated air from the primary refrigerant is discharged from the air -cooled outlet, provided in the upper part of the cooling chamber and the refrigerated air is introduced through a chilled air inlet, provided in the lower part of the freezing chamber into the cooling chamber and is blown again by the chilled air outlet. In this type of refrigerator it takes a relatively long time to cool down since the freezing chamber is cooled only by the circulation of refrigerated air. In fact, it takes about two hours to reduce water to ice at normal temperature in a freezing tray placed in a refrigeration chamber.

Various improvements have already been proposed to shorten the cooling time up to now. For example, the Japanese utility model published No. 52684/1978 proposes a heat exchanger referred to as "secondary refrigerant" in addition to the aforementioned primary refrigerant. This secondary refrigerator consists of a hollow vessel made up of a horizontal part and an upright part filled with a cooling medium. The upright part is kept in contact with the primary refrigerant while the horizontal part constitutes the bottom of a rapid freezing chamber ..... However, this type of refrigerator can only provide a more efficient heat exchange since the contact area between the refrigerant medium and the wall of the hollow vessel is limited. It is also difficult to absorb the heat from the object to be cooled and discharge the absorbed heat, with high efficiency, since the horizontal part for absorbing the heat and the upright part for discharging the heat have an identical structure.

Therefore an object of the invention is to provide a heat exchanger for refrigerators which is capable of operating with high heat exchange efficiency and this with a simple construction.

Another object of the invention is to provide a heat exchanger which can be removably mounted in a refrigerator and in which the coolant passages of the heat-absorbing type are arranged more densely while heat-radiating fins are provided on the heat discharge side so as to obtain a high efficiency of heat absorption and discharge. For this purpose, according to the invention, there is provided a heat exchanger adapted to be mounted and used in the vicinity of the different refrigerated source and comprising: a body - the heat exchanger consisting of a pair ... of-plates-joined together by lamination, the plates being of material having ... a-high-thermal-conductivity-the-body. of heat exchanger ... having-at least - a horizontal part and an upright part projecting upwards from one end of the horizontal part and integral with it, a plurality of first passages of the coolant formed between the two plates of the horizontally part, a plurality of second passages formed between the two plates of the upright part, and a refrigerant medium charged to circulate through the first and second passages of the coolant, the upright part being arranged in position-opppsta-to-source-of-refrigerated-air According to a preferred form of the invention, the first step of The coolant in the horizontal part is disposed at a higher level than that of the second coolant passage in the upright part. According to another preferred embodiment, the vertical part is provided, in correspondence with its areas near the second coolant passages, with a plurality of vent holes and heat radiation fins project horizontally from one of the lateral faces of the holes ventilation. Preferably, the second coolant passage consists of a plurality of vertical coolant passages disposed at a suitable passage, and a connecting coolant passage to which the upper ends of the vertical passage are connected in common. The connecting coolant passages can be raked from one end to the other.

According to the invention it is possible to obtain a large contact area between the refrigerant and the internal face of the wall of the passage of the refrigerant so as to significantly increase the effective area of absorption and discharge of heat, thus allowing the refrigerator to work efficiently. upper za. Since furthermore the first coolant passages of the horizontal part for heat absorption are densely arranged while second coolant passages in the heat exhaust part are arranged more rapidly, the heat exchange can be effected. with high efficiency regardless of the position and quantity of the objects to be refrigerated placed on the horizontal part. The inclination of the track connecting the second refrigerant passages allows the refrigerant medium condensed in this track to easily pass through the first refrigerant passages in the horizontal part so that the cooling of the refrigerant medium is facilitated for . further enhance the efficiency of heat exchange. It should also be noted that the heat exchanger, according to the invention, can be mounted in a removable manner in a freezing chamber by simply retaining it, in correspondence with the front faces of the two ends of the its horizontal part, by means of retaining projections provided on the side walls of the freezing chamber. Therefore, it is possible to mount the heat exchanger in the freezing chamber to form a fast-freezing chamber only when such rapid freezing is required.

Some preferred embodiments of the invention will now be described, by way of example only in relation to the accompanying drawings in which:

fig. 1 is a vertical sectional view of a first embodiment of the heat exchanger according to the invention, mounted in a freezing chamber;

fig. 2 is a front elevation view of the freezing chamber illustrated in FIG. 1 with its upper and lower doors, removed from fig. 3 is a front elevation view of the heat exchanger;

fig. 4 is a plan view of the heat exchanger illustrated in FIG. 3;

fig. 5 is a side elevation view of the heat exchanger illustrated in FIG. 3;

fig. 6 is a partially enlarged sectional view of the heat exchanger illustrated in FIG. 3, the section being made along the line 6-6 of fig. 3;

fig. 7 is a front elevational view of another embodiment of the heat exchanger;

fig. 8 is a sectional view, partially enlarged, taken along the line 8-8 of fig. 7; fig. 9 is a sectional view, partially enlarged, taken along the line 9-9 of fig. 7; and FIG. 10 is a plan view of the heat exchanger as illustrated in FIG. 7.

Referring to figs. 1 and 2, a refrigerator generically indicated by the reference number 11 has a casing which from a dividing wall 12 is divided into an upper freezing chamber 13. and a lower storage chamber 14. An upper door 15 and a door lower 16 are secured to the refrigerator 11, so as to close the front end of the freezing chamber 13 and the storage chamber 14. A cooling chamber 19 is located at the rear of the freezing- 13 .The-chamber of-raf. 19 is bounded by the rear wall 17 of the refrigerator 11 and by the rear partition plate 18 which is spaced from the rear wall 17. The cooling chamber 19 houses a primary coolant 21, a blower 22 for. the forced circulation of the air-cooled by the -coolant before-. flow 21 through the whole freezing chamber 13, and a motor 2! 3 for controlling the blower 22.

The primary coolant 21 is adapted to perform the cooling function performed by a compressor, a capillary tube and other limbs which are not illustrated.

o since the construction of these parts is well. ote, these parts are not illustrated in full detail in the drawings. The cooling chamber 19 also houses an accumulator which is not shown. A chilled air outlet 25 is formed in the upper part of the rear dividing plate 18 at a point opposite the fan 22. The chilled air outlet 25 has a plurality of guide fins 24 integral with the rear dividing plate 18 and protruding into the freezing chamber 13. Although not shown, more than one chilled air outlet 25 with guide fins are disposed along the width of the freezing compartment. 13 to evenly distribute the chilled air throughout the freezing chamber 13. The lower end of the rear partition plate 18 is slightly spaced from the upper surface of the partition wall 2. A lower partition plate 26 is formed at the lower end of the rear partition plate. so as to extend parallel to the partition plate 18. The space between the partition plate 18 and the lower partition plate 26 constitutes a passage 37 for the chilled air. The front end of the passage 37 opens into the freezing chamber 13. At its rear end, the passage 37 opens into the freezing chamber 19 As indicated by dotted lines in FIG. 1, an output 28; of refrigerated air which communicates with the storage chamber 14, is obtained from the dividing wall 12. A passage for the intake of refrigerated air is also obtained from the visual wall 12, one end of which opens near the refrigerant. 21 and the other end near the lower door 16 of the storage chamber 14. Consequently. the chilled air from the chilled air outlet 25 flows through the freezing chamber 13 into the chilled air passage 37. A. some of the chilled air is introduced from this passage 37 into the storage chamber 14 through the chilled air outlet 28 while the other part is fed to the primary coolant 21 for further cooling. The heated ascending air in the storage chamber 14 is likewise fed into the cooling chamber 1.9 through the chilled air intake passage 29, so as to be cooled in the cooling chamber 19.

A bracket plate 3 2 having a plurality of orifices 31 for the passage of fresh air is provided at a height. intermediate in the freezing chamber 13. As illustrated in fig. 2, the space on the cantilever plate 32 is divided in the width direction into an ice making chamber 35 and a quick freezing chamber 36 by means of a vertical partition plate 34 having an upper end which is attached to the upper plate 33 of the refrigerator 11. Consequently, the space in the freezing chamber 13 is divided into three compartments namely the upper rapid freezing chamber 36, an intermediate freezing chamber 37 between the rapid freezing chamber 36 and the shelf plate 32, and a lower freezing chamber 38 between the shelf plate 32 and the lower partition plate 26. Intermediate doors 39 and 40 are secured respectively to the front side of the quick freezing chamber 36 and to the lower freezing chamber 38.

The rapid freezing chamber 36 is constituted by a heat exchanger 41 composed of a heat pipe of the thermal siphon type. This heat exchanger 41 in section has a substantially L-shape and is composed of a horizontal part 42 and an upright part 43 integral with each other. The upright portion 43 is disposed in a position opposite the refrigerated air outlet 25 in the rear partition 18 with a gap 44 between them. However, the gap 44 can also be omitted, i.e., there upright part 43 can be positioned in close contact with the outlet. 25 of refrigerated air, in the partition plate. rear 1 8. The heat exchanger.4 1 is removably mounted in the freezing chamber 36. rapid, so that its horizontal portion 42 extends substantially horizontally. More specifically, a widthwise end of the horizontal portion 42 of the heat exchanger 41 is retained by a retaining projection 45 provided at the bottom of the partition plate 34 while the other end of the heat exchanger is retained. from a ledge of. retainer 46 located, at the right inner face of the freezing chamber 13 as. yes, you can see in fig. 2.

Referring. in figs 3 to 6 which show the details of the exchanger. 41, a flat cop-of-rectangular-plates obtained. -from-a material having-a high-thermal-conductivity, -eg. aluminum, copper-or-like, is superimposed on each other with carbon powder or a similar material placed between the opposite faces of these plates. The coal powder forms a closed lattice which constitutes a passage 47 for a refrigerant medium. These plates are then laminated at high pressure so as to be joined together to forming an integral structure which is then folded into an L-like shape, having the horizontal part 2 and the upright part 43. Thereafter the part having the closed lattice produced by the coal dust is expanded to form the passage 47 for the -mez zo refrigerant. The passage 47 is then filled with a refrigerant medium 50 of the freon type, e.g. R12. The part of the passage 47 for the cooling medium in the upright part 43 consists of a horizontal passage 48 for the cooling medium, formed in the upper part of the upright part 43 and extending in the direction of the width of the latter, and by a plurality of passages vertical passages 49-for the cooling medium, extending from the eastern passages 48 at deguated intervals. On the other hand, the portion of the passage 47 for the cooling medium in the horizontal part 42 consists of a plurality of longitudinal passages 51 for the standing medium, which communicate with the vertical passages 49 in the cooling medium, by transversal passages 52 53, 54 for the cooling medium, which interconnect the longitudinal passages 51 in the form of three parallel rectangular waves, and by a horizontal passage 55 for the cooling medium, to which the other ends of the longitudinal passages are connected in common. Therefore in this heat exchanger 41 the passage 47 for the cooling medium in the horizontal part 42 has a higher density than that in the upright part 43. The liquid cooling medium 50 in the horizontal part 42 evaporates in the gaseous phase by absorption of heat from the object to be cooled, or load. The gaseous refrigerant medium then moves to the horizontal part 42 and is condensed to the liquid phase as it is cooled by the refrigerated air blown by the refrigerated air outlet 25 and which strikes the riser part 43. Then the liquefied gaseous medium returns to the horizontal by gravity. Thus heat exchanger 41 works as a thermal siphon.

A plurality of ventilation holes 56 is present in the area of the upright part 43 of the cadore exchanger 41 which is devoid of the passages 47 for the cooling medium, i.e. substantially the central limbs between the adjacent vertical passages 49 for the cooling medium. Heat-radiating fins 57 are integral with the upright portion at points just below the respective ventilation holes 56. Needless to say, these heat-radiating fins 57 may protrude into the quick-freezing chamber 36, as indicated from

strokes and points in fig. 6.

During operation, the refrigerated refrigerant air is brought into the cooling chamber 19 f and conveyed upwards by the blower 22 and is sent to the freezing chamber-13, through the refrigerated air outlet 25. cooled air flows through the interspace 44 and a part of this cooled air is introduced into the ventilation holes 56, while it is guided by the heat radiation fins 57 - of the mounting part 43 and further forward to the intermediate chamber - freezing de-icing 37 beyond the freezing chamber 36 -rap do. The other part of the chilled air is introduced into the intermediate freezing chamber 37 after coming into contact with the heat radiation fins 57 in the upright part and in the door. test 47 of the cooling medium these fins having been cooled by this contact. The cooled air introduced into the intermediate freezing chamber 37 returns to the primary coolant 21 in the cooling chamber 19 through the lower freezing chamber 38 and the chilled air passage 52. Thus the chilled air from the primary coolant 21 is forced by the blower 22 to circulate through the entire freezing chamber 13. Thus the chilled air, which has a large amount of heat-cooled, is introduced into the cooling chamber 36. rapid freezing-to -cool rapidly the object in-this-career. Assuming now that a load to be refrigerated is placed in the rapid freezing chamber 36, e.g. an ice plate 58, in this case the water or ice in the gel plate 58 transmits heat to the cooling medium introduced in the passage 47 of the cooling medium itself, of the horizontal part 42 of the heat exchanger 41, thus evaporating this medium r refrigerant. Thus the ice plate 53 is cooled while the evaporated refrigerant medium flows upwards in the passage 47 in the upright part 43 In part because the refrigerated air, which has a large amount of cooled heat and which comes from The cooled air outlet strikes the fins 57 and the parts surrounding the coolant passage 47, and in part because this cooled air passes through the ventilation holes 56, the gaseous coolant medium flowing up in the upright part is effectively cooled and condensed to the liquid phase which in turn returns to the passage 47 of the cooling medium in the horizontal part 42. Consequently, the ice plate 58 in the rapid freezing chamber 36 is cooled by both the chilled air passing through the ventilation holes 56 and that passing through the heat exchanger 41. In sequence, the time required for cooling can be considerably shortened. For example, while in the conventional refrigerator, which does not have a heat exchanger.41, it takes about 2 hours for the complete freezing of the water to room temperature in the ice pan .58, the refrigerator equipped with the exchanger. -of- heat 41 can. freeze the same amount of water on ice within a period of 30 minutes which is much shorter. Since furthermore, the heat exchanger 41 is simply supported at its horizontal portion 42 by the retaining projections 45 and 46, the heat exchanger 41 can be readily disassembled for cleaning purposes or the like refrigerate, like-the-dish, of. ice 58, can be introduced and removed from the rapid freezing chamber.

Fig. 7 shows another embodiment of the heat exchanger 41 according to the invention, which has a different shape of the passage 47 for the refrigerating medium. In this embodiment, the horizontal passage 48 for the cooling medium in the upright portion 43 is shaped like a mountain, convex upward in its center length and with two wings tapering gently downward. This shape of the horizontal passage 48 for the cooling medium facilitates the movement of the liquid cooling medium, condensed in this passage 61, and its entry into the passage 47 of the cooling medium itself in the horizontal part. As illustrated in Figure 10, in this embodiment the transverse linear passages 62, 63 for the cooling medium are formed at the front and rear end portions of the horizontal portion 42. The transverse passage 62 for the cooling medium communicates with the vertical passages 49 for the cooling medium in the upright portion 43. A plurality of longitudinal passages 64 for the cooling medium are connected between the transverse passages 62 and 63 for the cooling medium. The number of longitudinal passages 64 for the cooling medium is greater than that of the vertical passages 49 for the cooling medium. Consequently, the horizontal part 42 of the heat exchanger 41 has a density of passages for the cooling medium higher than that of the upright part 43. In this embodiment the heat-radiating fins can be formed by two different methods which are illustrated in FIG. 7. More specifically in the left part of fig. 7 the heat irradiation fins 65 are integral with the mo-nant part 43 at the left side of the ventilation holes 56 while in the part of the right half of fig. 7 the heat radiating fins 66 are integral with the upright part 43 to the lower side of the ventilation holes 56. Needless to say, the upstream-shaped passage 61 for the cooling medium, having the central part conves upwards in the upright part 43, it can also be replaced with an inclined passage that tapers in a linear form from one end to the other in the direction of the width of the upright part 43.

The embodiments of the invention described above have a plurality of ventilation holes 56 and fins 57, 65, 66 for radiating heat, provided in the upright part 43 of the heat exchanger -41- -These ventilation holes, and heat radiation fins are -dest born-to-improve the cooling effect and are not indispensable - in fact-even the-ventilation-holes alone-can-ensure an improvement sensitive-of-the-effect of. cooling down. If no ventilation holes are foreseen, the upright part 43 is positioned at an adequate distance from the rear partition plate 18 in order to unmold one. gap between the upper end of the upright part 43 and the upper plate 33. This gap can be used effectively as a passage for the supply of cooled air to the rapid freezing chamber 36.

Although the invention has been described with specific reference to a refrigerator of the. so-called forced refrigerated air circulation type (blower type), for those skilled in the art it will be evident that the inversion can also be applied to a type of natural refrigerated air convection refrigerator, in which the freezing compartment 13 is surrounded by an evaporator to allow the cooling of an object by conduction and natural convection of heat. For this purpose, it is sufficient to keep the upright part 43 of the heat exchanger 41 in contact with the vertical wall of the evaporator in the freezing chamber.

It should also be noted that the heat exchanger need not always be the described heat pipe of the thermal siphon type and that other types of heat exchanger can also be used effectively as a heat exchanger. such as a heat pipe of the capillary type, having stoppers e.g. a structure - consisting of a plurality of layers of metal meshes - and having a degree of capillary force, provided at the inner faces of the passages of the cooling medium.

Claims (1)

CLAIMS 1. Heat exchanger adapted to be mounted and used near the source of chilled air, comprising: a heat exchanger body consisting of a pair of plates joined together by lamination, said plates being of material having a high thermal conductivity , said heat exchanger body having at least one horizontal wall and an upright part projecting upwardly from one end of the horizontal part and integral with it, a plurality of first coolant passages formed between the two plates of said horizontal wall, one plurality of second coolant passages formed between the two plates in said upright part, and a coolant medium charged to circulate through the first and second coolant passages, said upright part being arranged at one point, opposite said source of refrigerated air. 2. A heat exchanger according to claim. 1, in which the density of said horizontal coolant passages in said part is greater than that of said second coolant passages in said upright part. 3. A heat exchanger according to claim 1, wherein a plurality of ventilation holes are provided between the second adjacent coolant passages in said upright part. 4. A heat exchanger according to claim 3, wherein heat-radiating fins are provided on one of the side faces of said ventilation holes so as to extend horizontally from said side faces. 5. The heat exchanger of claim 1 wherein said first coolant passages in said riser portion comprise a plurality of vertical coolant passages disposed at suitable intervals, and a connecting coolant passage to which the vertical coolant are connected in common. 6. A heat exchanger according to claim 5, wherein said connecting coolant passage tapers from one end thereof to the other 7. A heat exchanger according to claim wherein said heat exchanger is constituted by a heat pipe of the thermal siphon type, in which the condensed and liquid refrigerant medium made in said upright part moves under the force of gravity to enter said horizontal part, 8. Refrigerator of the forced circulation type in which the cooled air coming from a first cooler is fed into a cooling chamber through a cooled air outlet and is subjected to forced circulation in said cooling chamber - the refrigerator comprising a heat exchanger consisting of a pair of plates joined together by lamination, said plates being of material having a high conductivity - thermal, called - body of - heat exchanger. having at least one part, horizontal and a moving part projecting upwards from one end of the horizontal part and integral with it, a plurality of first passages of the refrigerant located between the two plates of said horizontal part, a plurality of second refrigerant passages located between the two plates in said upright part, and a refrigerant means charged so as to circulate through the first and second coolant passages, said upright part being disposed at a point opposite to said source of air. chilled; e means for supporting said heat exchanger so that said upright part is at an opposite point to said cooled air outlet; in which said horizontal part divides the space. in said ... freezing chamber so as to form a rapid_freezing chamber .. 9. A refrigerator according to claim 8, wherein said first coolant passages in said horizontal part have a higher density than said second coolant passages in said upright part. Refrigerator according to claim 8, wherein said horizontal part has a plurality. the ventilation holes formed in the parts between the first adjacent refrigerant passages whereby the refrigerated air coming from said refrigerated air outlet is fed into said rapid freezing chamber. 11. A refrigerator according to claim 10, wherein heat radiation fins are provided on one of the lateral faces of said outlet holes so as to project horizontally from said lateral face. 1 2 refrigerator-according-to-claim 8, wherein said upright part-is-disposed-at an adequate distance -from said- outlet - of refrigerated air 13. A refrigerator according to claim 8, wherein said supporting means comprise retaining projections secured to the walls of said freezing chamber and having an upper face for retaining the lower side of said horizontal part of the said heat exchanger. 14. Refrigerator according to claim 8, wherein said heat exchanger is constituted by a heat pipe, of the thermal siphon type, in which the condensed and liquefied refrigerant medium, in said upright part, is conveyed in said horizontal part thanks to the force of gravity.